Bitwise XOR operator in JavaScript

Question

Why is this:

console.log("1100" ^ "0001")
=> 1101 // as expected

console.log("1100" ^ "1001")
=> 1957 // ???

Please explain. Thanks.

Answer 1

Those numbers are interpreted as decimal numbers.

Try:

console.log(parseInt("1100", 2) ^ parseInt("1001", 2))

Of course the answer (0101) is printed in decimal (5).

The JavaScript token grammar supports numbers in decimal, octal, and hex, but not binary. Thus:

console.log(0xC0 ^ 0x09)

The first one worked, by the way, because 1100 (decimal) is 1101 (decimal) after the xor with 1.